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Unger, Holger
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Unger, Holger
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- PublicationThe relationship between markers of antenatal iron stores and birth outcomes differs by malaria prevention regimen-a prospective cohort study.(2021-10-05)
; ;Laurita Longo, Valentina ;Bleicher, Andie ;Ome-Kaius, Maria ;Karl, Stephan ;Simpson, Julie A ;Karahalios, Amalia ;Aitken, Elizabeth HRogerson, Stephen JBACKGROUND: Iron deficiency (ID) has been associated with adverse pregnancy outcomes, maternal anaemia, and altered susceptibility to infection. In Papua New Guinea (PNG), monthly treatment with sulphadoxine-pyrimethamine plus azithromycin (SPAZ) prevented low birthweight (LBW; <2500 g) through a combination of anti-malarial and non-malarial effects when compared to a single treatment with SP plus chloroquine (SPCQ) at first antenatal visit. We assessed the relationship between ID and adverse birth outcomes in women receiving SPAZ or SPCQ, and the mediating effects of malaria infection and haemoglobin levels during pregnancy. METHODS: Plasma ferritin levels measured at antenatal enrolment in a cohort of 1892 women were adjusted for concomitant inflammation using C-reactive protein and α-1-acid glycoprotein. Associations of ID (defined as ferritin <15 μg/L) or ferritin levels with birth outcomes (birthweight, LBW, preterm birth, small-for-gestational-age birthweight [SGA]) were determined using linear or logistic regression analysis, as appropriate. Mediation analysis assessed the degree of mediation of ID-birth outcome relationships by malaria infection or haemoglobin levels. RESULTS: At first antenatal visit (median gestational age, 22 weeks), 1256 women (66.4%) had ID. Overall, ID or ferritin levels at first antenatal visit were not associated with birth outcomes. There was effect modification by treatment arm. Amongst SPCQ recipients, ID was associated with a 81-g higher mean birthweight (95% confidence interval [CI] 10, 152; P = 0.025), and a twofold increase in ferritin levels was associated with increased odds of SGA (adjusted odds ratio [aOR] 1.25; 95% CI 1.06, 1.46; P = 0.007). By contrast, amongst SPAZ recipients, a twofold increase in ferritin was associated with reduced odds of LBW (aOR 0.80; 95% CI 0.67, 0.94; P = 0.009). Mediation analyses suggested that malaria infection or haemoglobin levels during pregnancy do not substantially mediate the association of ID with birth outcomes amongst SPCQ recipients. CONCLUSIONS: Improved antenatal iron stores do not confer a benefit for the prevention of adverse birth outcomes in the context of malaria chemoprevention strategies that lack the non-malarial properties of monthly SPAZ. Research to determine the mechanisms by which ID protects from suboptimal foetal growth is needed to guide the design of new malaria prevention strategies and to inform iron supplementation policy in malaria-endemic settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT01136850 .2265 - PublicationAeromedical retrieval for suspected preterm labour or rupture of membranes in the Northern Territory, Australia: may some cases be safely not retrieved?(2024-11-30)
;Langston-Cox, Annie ;Warton, Emily ;Tipping, Nadine ;Odgers, Harrison L; ;Goni, Sherihan; ; Suspected preterm labour (PTL) and prelabour rupture of membranes (PPROM) are common indications for aeromedical retrieval in the Top End, Northern Territory, Australia, where many women reside remotely and preterm birth (< 37 completed weeks of gestation) is common. The primary objective of this study was to determine rate of delivery during the index admission following aeromedical transfers from remote clinics to Royal Darwin Hospital for suspected PTL/PPROM.A retrospective cohort study of aeromedical transfers for suspected PTL/PPROM from 1 January 2020 to 31 July 2022 was undertaken. Transfers were identified through CareFlight, the regional air ambulance service, and complemented with data from hospital records. Clinical and sociodemographic characteristics were compared by delivery status during the index (post-retrieval) admission using parametric and non-parametric tests and multivariable linear regression analysis.238 women with singleton pregnancies were retrieved for suspected PPROM (n = 77, 32.4%) or PTL (n = 161, 67.6%), together accounting for 49.2% of all obstetric transfers (n = 483). Of 77 patients transferred for suspected PPROM, 47 (61.0%) had ruptured membranes confirmed on arrival, and 45 (95.7%) of them delivered during the index admission. None of the 30 women transferred for suspected PPROM with intact membranes on arrival delivered during the index admission. Of 161 patients transferred for suspected PTL, 13 (8.1%) had ruptured membranes confirmed on arrival, and 12 (92.3%) of them delivered during the index admission. Amongst women transferred for suspected PTL with intact membranes confirmed on arrival, 14.9% (22/149) delivered during the index admission. Prior to arrival, 120 women (50.4%) had a documented speculum examination, and 15 (6.3%) and 9 (3.8%) had cervicovaginal swab tests to assess their risks of a PPROM and PTL, respectively. Half of women who did not deliver during the index admission had received antenatal corticosteroids (n = 76).Many aeromedical retrievals for suspected PTL/PPROM did not result in delivery during the index admission. Women retrieved for suspected PPROM with intact membranes on arrival were less likely to deliver. Upskilling remote clinic staff and better point-of-care testing may reduce retrievals and unnecessary interventions. Prospective cohort studies designed to enable accurate prediction of which cases can be safely not retrieved are required.Not applicable.8 - PublicationImpact on pregnancy outcomes of intermittent preventive treatment with sulfadoxine-pyrimethamine in urban and peri-urban Papua New Guinea: a retrospective cohort study.(2024-07-05)
;Cellich, Philip; ;Rogerson, Stephen JMola, Glen D LIntermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) reduces malaria-attributable adverse pregnancy outcomes and may also prevent low birth weight (< 2,500 g) through mechanisms independent of malaria. Malaria transmission in Papua New Guinea (PNG) is highly heterogeneous. The impact of IPTp-SP on adverse birth outcomes in settings with little or no malaria transmission, such as PNG's capital city Port Moresby, is unknown.A retrospective cohort study was conducted amongst HIV-negative women with a singleton pregnancy who delivered at Port Moresby General Hospital between 18 July and 21 August 2022. The impact of IPTp-SP doses on adverse birth outcomes and anaemia was assessed using logistic and linear regression models, as appropriate.Of 1,140 eligible women amongst 1,228 consecutive births, 1,110 had a live birth with a documented birth weight. A total of 156 women (13.7%) did not receive any IPTp-SP, 347 women (30.4%) received one, 333 (29.2%) received two, and 304 (26.7%) received the recommended ≥ 3 doses of IPTp-SP. A total of 65 of 1,110 liveborn babies (5.9%) had low birth weight and there were 34 perinatal deaths (3.0%). Anaemia (haemoglobin < 100 g/L) was observed in 30.6% (243/793) of women, and 14 (1.2%) had clinical malaria in pregnancy. Compared to women receiving 0-1 dose of IPTp-SP, women receiving ≥ 2 doses had lower odds of LBW (adjusted odds ratio [aOR] 0.50; 95% confidence interval [CI] 0.26, 0.96), preterm birth (aOR 0.58; 95% CI 0.32, 1.04), perinatal death (aOR 0.49; 95% CI 0.18, 1.38), LBW/perinatal death (aOR 0.55; 95% CI 0.27, 1.12), and anaemia (OR 0.50; 95% CI 0.36, 0.69). Women who received 2 doses versus 0-1 had 45% lower odds of LBW (aOR 0.55, 95% CI 0.27, 1.10), and a 16% further (total 61%) reduction with ≥ 3 doses (aOR 0.39, 95% CI 0.14, 1.05). Birth weights for women who received 2 or ≥ 3 doses versus 0-1 were 81 g (95% CI -3, 166) higher, and 151 g (58, 246) higher, respectively.Provision of IPTp-SP in a low malaria-transmission setting in PNG appears to translate into substantial health benefits, in a dose-response manner, supporting the strengthening IPTp-SP uptake across all transmission settings in PNG.3 - PublicationDeveloping a multivariate prediction model of antibody features associated with protection of malaria-infected pregnant women from placental malaria.(2021-06-29)
;Aitken, Elizabeth H ;Damelang, Timon ;Ortega-Pajares, Amaya ;Alemu, Agersew ;Hasang, Wina ;Dini, Saber; ;Ome-Kaius, Maria ;Nielsen, Morten A ;Salanti, Ali ;Smith, Joe ;Kent, Stephen ;Hogarth, P Mark ;Wines, Bruce D ;Simpson, Julie A ;Chung, AmyRogerson, Stephen JBACKGROUND: Plasmodium falciparum causes placental malaria, which results in adverse outcomes for mother and child. P. falciparum-infected erythrocytes that express the parasite protein VAR2CSA on their surface can bind to placental chondroitin sulfate A. It has been hypothesized that naturally acquired antibodies towards VAR2CSA protect against placental infection, but it has proven difficult to identify robust antibody correlates of protection from disease. The objective of this study was to develop a prediction model using antibody features that could identify women protected from placental malaria. METHODS: We used a systems serology approach with elastic net-regularized logistic regression, partial least squares discriminant analysis, and a case-control study design to identify naturally acquired antibody features mid-pregnancy that were associated with protection from placental malaria at delivery in a cohort of 77 pregnant women from Madang, Papua New Guinea. RESULTS: The machine learning techniques selected 6 out of 169 measured antibody features towards VAR2CSA that could predict (with 86% accuracy) whether a woman would subsequently have active placental malaria infection at delivery. Selected features included previously described associations with inhibition of placental binding and/or opsonic phagocytosis of infected erythrocytes, and network analysis indicated that there are not one but multiple pathways to protection from placental malaria. CONCLUSIONS: We have identified candidate antibody features that could accurately identify malaria-infected women as protected from placental infection. It is likely that there are multiple pathways to protection against placental malaria. FUNDING: This study was supported by the National Health and Medical Research Council (Nos. APP1143946, GNT1145303, APP1092789, APP1140509, and APP1104975).1172 - PublicationExploring menstrual products: A systematic review and meta-analysis of reusable menstrual pads for public health internationally.(2021-09-24)
;van Eijk, Anna Maria ;Jayasinghe, Naduni ;Zulaika, Garazi ;Mason, Linda ;Sivakami, Muthusamy; Phillips-Howard, Penelope ABACKGROUND: Girls and women need effective, safe, and affordable menstrual products. Single-use menstrual pads and tampons are regularly provided by agencies among resource-poor populations. Reusable menstrual pads (RMPs: fabric layers sewn together by an enterprise for manufacture of menstrual products) may be an effective alternative. METHODS: For this review (PROSPERO CRD42020179545) we searched databases (inception to November 1, 2020) for quantitative and qualitative studies that reported on leakage, acceptability, or safety of RMPs. Findings were summarised or combined using forest plots (random-effects meta-analysis). Potential costs and environmental savings associated with RMPs were estimated. RESULTS: A total of 44 studies were eligible (~14,800 participants). Most were conducted in low- and middle-income countries (LMIC, 78%), and 20% in refugee settings. The overall quality of studies was low. RMP uptake in cohort studies ranged from 22-100% (12 studies). One Ugandan trial among schoolgirls found leakage with RMPs was lower (44.4%, n = 72) compared to cloths (78%, n = 111, p<0.001). Self-reported skin-irritation was 23.8% after 3 months among RMP-users in a Ugandan cohort in a refugee setting (n = 267), compared to 72.8% at baseline with disposable pad use. There were no objective reports on infection. Challenges with washing and changing RMP were reported in LMIC studies, due to lack of water, privacy, soap, buckets, and sanitation/drying facilities. Among 69 brands, the average price for an RMP was $8.95 (standard deviation [sd] $5.08; LMIC $2.06, n = 10, high-income countries [HIC] $10.11), with a mean estimated lifetime of 4.3 years (sd 2.3; LMIC 2.9, n = 11; HIC 4.9 years, n = 23). In 5-year cost-estimates, in LMICs, 4-25 RMPs per period would be cheaper (170-417 US$) than 9-25 single-use pads, with waste-savings of ~600-1600 single-use pads. In HICs, 4-25 RMPs would be cheaper (33-245 US$) compared to 20 single-use tampons per period, with waste-savings of ~1300 tampons. CONCLUSION: RMPs are used internationally and are an effective, safe, cheaper, and environmentally friendly option for menstrual product provision by programmes. Good quality studies in this field are needed.1871 - PublicationFetal sex and risk of pregnancy-associated malaria in Plasmodium falciparum-endemic regions: a meta-analysis.(2023)
; ;Hadiprodjo, Anastasia Jessica ;Gutman, Julie R ;Briand, Valerie ;Fievet, Nadine ;Valea, Innocent ;Tinto, Halidou ;D'Alessandro, Umberto ;Landis, Sarah H ;Ter Kuile, Feiko ;Ouma, Peter ;Oneko, Martina ;Mwapasa, Victor ;Slutsker, Laurence ;Terlouw, Dianne J ;Kariuki, Simon ;Ayisi, John ;Nahlen, Bernard ;Desai, Meghna ;Madanitsa, Mwayi ;Kalilani-Phiri, Linda ;Ashorn, Per ;Maleta, Kenneth ;Tshefu-Kitoto, Antoinette ;Mueller, Ivo ;Stanisic, Danielle ;Cates, Jordan ;Van Eijk, Anna Maria ;Ome-Kaius, Maria ;Aitken, Elizabeth HRogerson, Stephen JIn areas of moderate to intense Plasmodium falciparum transmission, malaria in pregnancy remains a significant cause of low birth weight, stillbirth, and severe anaemia. Previously, fetal sex has been identified to modify the risks of maternal asthma, pre-eclampsia, and gestational diabetes. One study demonstrated increased risk of placental malaria in women carrying a female fetus. We investigated the association between fetal sex and malaria in pregnancy in 11 pregnancy studies conducted in sub-Saharan African countries and Papua New Guinea through meta-analysis using log binomial regression fitted to a random-effects model. Malaria infection during pregnancy and delivery was assessed using light microscopy, polymerase chain reaction, and histology. Five studies were observational studies and six were randomised controlled trials. Studies varied in terms of gravidity, gestational age at antenatal enrolment and bed net use. Presence of a female fetus was associated with malaria infection at enrolment by light microscopy (risk ratio 1.14 [95% confidence interval 1.04, 1.24]; P = 0.003; n = 11,729). Fetal sex did not associate with malaria infection when other time points or diagnostic methods were used. There is limited evidence that fetal sex influences the risk of malaria infection in pregnancy.736 - PublicationAssociations of maternal iron deficiency with malaria infection in a cohort of pregnant Papua New Guinean women.(2022-05-26)
; ;Bleicher, Andie ;Ome-Kaius, Maria ;Aitken, Elizabeth HRogerson, Stephen JBACKGROUND: Iron deficiency (ID) is common in malaria-endemic settings. Intermittent preventative treatment of malaria in pregnancy (IPTp) and iron supplementation are core components of antenatal care in endemic regions to prevent adverse pregnancy outcomes. ID has been associated with reduced risk of malaria infection, and correspondingly, iron supplementation with increased risk of malaria infection, in some studies. METHODS: A secondary analysis was conducted amongst 1888 pregnant women enrolled in a malaria prevention trial in Papua New Guinea. Maternal ID was defined as inflammation-corrected plasma ferritin levels < 15 μg/L at antenatal enrolment. Malaria burden (Plasmodium falciparum, Plasmodium vivax) was determined by light microscopy, polymerase chain reaction, and placental histology. Multiple logistic and linear regression analyses explored the relationship of ID or ferritin levels with indicators of malaria infection. Models were fitted with interaction terms to assess for modification of iron-malaria relationships by gravidity or treatment arm. RESULTS: Two-thirds (n = 1226) and 13.7% (n = 258) of women had ID and peripheral parasitaemia, respectively, at antenatal enrolment (median gestational age: 22 weeks), and 18.7% (120/1,356) had evidence of malaria infection on placental histology. Overall, ID was associated with reduced odds of peripheral parasitaemia at enrolment (adjusted odds ratio [aOR] 0.50; 95% confidence interval [95% CI] 0.38, 0.66, P < 0.001); peripheral parasitaemia at delivery (aOR 0.68, 95% CI 0.46, 1.00; P = 0.050); and past placental infection (aOR 0.35, 95% CI 0.24, 0.50; P < 0.001). Corresponding increases in the odds of infection were observed with two-fold increases in ferritin levels. There was effect modification of iron-malaria relationships by gravidity. At delivery, ID was associated with reduced odds of peripheral parasitaemia amongst primigravid (AOR 0.44, 95% CI 0.25, 0.76; P = 0.003), but not multigravid women (AOR 1.12, 95% CI 0.61, 2.05; P = 0.720). A two-fold increase in ferritin associated with increased odds of placental blood infection (1.44, 95% CI 1.06, 1.96; P = 0.019) and active placental infection on histology amongst primigravid women only (1.24, 95% CI 1.00, 1.54; P = 0.052). CONCLUSIONS: Low maternal ferritin at first antenatal visit was associated with a lower risk of malaria infection during pregnancy, most notably in primigravid women. The mechanisms by which maternal iron stores influence susceptibility to infection with Plasmodium species require further investigation.3320 - PublicationAssessing the Role of Echocardiography in Pregnancy in First Nations Australian Women: Is it an Underutilised Resource?(2024-09-01)
;Marangou, James ;Ferguson, Dominic; ; ; ; Rheumatic heart disease (RHD) remains prevalent within First Nations Australian communities. RHD is more common in females and peak prevalence corresponds with childbearing age. Significant valvular disease can complicate pregnancy. Current practice in Northern Australia is to refer pregnant women for echocardiography if there are signs or symptoms of possible cardiac pathology or a history of acute rheumatic fever (ARF) or RHD. It is not currently routine practice to offer echocardiographic screening for all pregnant women at high risk of RHD.This study aimed to assess the current referral practices for echocardiography and disease patterns in pregnant women in the Northern Territory, Australia-a region with a known high prevalence of RHD in the First Nations population.A retrospective analysis of all echocardiography referrals of pregnant women over a 4-year period was performed. Data included indication for echocardiography, clinical history, echocardiographic findings, and location of delivery. Comparisons were made using Fisher's exact and Mann-Whitney U tests.A total of 322 women underwent echocardiography during pregnancy: 195 First Nations and 127 non-Indigenous women (median age, 25 vs 30 years, respectively; p<0.01). Indications for echocardiography differed by ethnicity, with history of ARF or RHD being the most common indication in First Nations women, and incidental murmur the most common in non-Indigenous women. First Nations women were more likely to have abnormal echocardiograms (35.9% vs 11.0% in non-Indigenous women; p<0.01) or a history of ARF or RHD (39.5% vs 0.8%; p<0.01), but less likely to have documented cardiac symptoms as an indication for echocardiography (8.2% vs 20.5%; p<0.01). New cardiac diagnoses were made during pregnancy in 11 (5.6%) First Nations and two (1.6%) non-Indigenous women (p=0.02). Moderate or severe valve lesions were detected in 26 (13.3%) First Nations women (all previously diagnosed), and 11 (5.6%) had previous cardiac surgery. No severe valve lesions were identified in the non-Indigenous group. Interstate transfer to a tertiary centre with valve intervention services was required during pregnancy or the puerperium for 12 (6.2%) First Nations women and no non-Indigenous women.Amongst pregnant women in the Northern Territory who had an indication for echocardiography, First Nations women were more likely to have abnormal echocardiograms. This was mainly due to valvular disease secondary to RHD. Cardiac symptoms were infrequently recorded as an indication for echocardiography in First Nations women, suggesting possible underappreciation of symptoms. Having a low threshold for echocardiographic investigation, including consideration of universal screening during pregnancy, is important in a high RHD-burden setting such as ours. A better understanding of the true prevalence and spectrum of disease severity in this population would enable health services to invest in appropriate resources.3 - PublicationA better start to life: Risk factors for, and prevention of, preterm birth in Australian First Nations women - a narrative review.(2021-08-28)
; ;Langston-Cox, AnnieThe unacceptable discrepancies in health outcomes between First Nations and non-Indigenous Australians begin at birth. Preterm birth (birth before 37 completed weeks of gestation) is a major contributor to adverse short- and long-term health outcomes and mortality. Australian First Nations infants are more commonly born too early. No tangible reductions in preterm births have been made in First Nations communities. Factors contributing to high preterm birth rates in Australian First Nations infants are reviewed and interventions to reduce preterm birth in Australian First Nations women are discussed. More must be done to ensure Australian First Nations infants get a better start to life. This can only be achieved with ongoing and improved research in partnership with Australian First Nations peoples.4555 - PublicationAntibody mediated activation of natural killer cells in malaria exposed pregnant women.(2021-02-18)
;Damelang, Timon ;Aitken, Elizabeth H ;Hasang, Wina ;Lopez, Ester ;Killian, Martin; ;Salanti, Ali ;Shub, Alexis ;McCarthy, Elizabeth ;Kedzierska, Katherine ;Lappas, Martha ;Kent, Stephen J ;Rogerson, Stephen JChung, Amy WImmune effector responses against Plasmodium falciparum include antibody-mediated activation of innate immune cells, which can induce Fc effector functions, including antibody-dependent cellular cytotoxicity, and the secretion of cytokines and chemokines. These effector functions are regulated by the composition of immunoglobulin G (IgG) Fc N-linked glycans. However, a role for antibody-mediated natural killer (NK) cells activation or Fc N-linked glycans in pregnant women with malaria has not yet been established. Herein, we studied the capacity of IgG antibodies from pregnant women, with placental malaria or non-placental malaria, to induce NK cell activation in response to placental malaria-associated antigens DBL2 and DBL3. Antibody-mediated NK cell activation was observed in pregnant women with malaria, but no differences were associated with susceptibility to placental malaria. Elevated anti-inflammatory glycosylation patterns of IgG antibodies were observed in pregnant women with or without malaria infection, which were not seen in healthy non-pregnant controls. This suggests that pregnancy-associated anti-inflammatory Fc N-linked glycans may dampen the antibody-mediated activation of NK cells in pregnant women with malaria infection. Overall, although anti-inflammatory glycans and antibody-dependent NK cell activation were detected in pregnant women with malaria, a definitive role for these antibody features in protecting against placental malaria remains to be proven.876